This invention relates to delivering and fetching font information between a host computer and an output device, such as a printer.
Characters of one style are organized into fonts. Roman style fonts, such as Times-Roman (see Appendix A, which shows the Times-Roman character set) and Helvetica include relatively small numbers of characters (the Roman letters, the arabic numbers, and symbols). The amount of information needed to represent the characters of a Roman font is generally small enough to allow it to be stored within the memory of a conventional computer printer.
Other fonts, for example, fonts for Asian languages, typically include so many characters or symbols that complete font information cannot conveniently be stored at one time within the printer's internal memory.
One way to store the Asian font information is in an external hard disk connected to the printer.
Another known approach is to store the font information in the host computer and use it to deliver nonscalable bit map character glyphs from the computer to the printer, over a single communication channel, as needed.